Was He Swiss?

In response to:

A very small correction to Keith Thomas’s fascinating review of Hugh Trevor-Roper’s work on Theodore de Mayerne [“A Highly Paradoxical Historian,” NYR, April 12]. Paracelsus was as much Swiss as German, if not more so.

Of course, it all depends what you mean by nationality in an age when it mattered less than today. It reminds me of an incident when I was working in Brussels in the 1960s and an inexperienced secretary addressed an envelope to the Swiss office as “Zurich, Germany.”

The offending envelope was returned by the Swiss office with a handwritten annotation saying: “Noch nicht” (Not yet).